United States Patent
`
`
`
`
`Eggers et al.
`
`
`
`[191
`
`
`
`
`
`
`||||l|l|I|||l||||||||l||||||l|||l||||||||l||l|l|||I|||||Illllllllllllllllll
`USO05484436A
`
`
`
`Patent Number:
`
`
`
`Date of Patent:
`[45]
`
`[11]
`
`5,484,436
`
`
`Jan. 16, 1996
`
`
`
`
`
`[54]
`
`
`
`[75]
`
`
`
`[73]
`
`
`[21]
`
`[22]
`
`
`
`
`
`[63]
`
`
`
`[51]
`[52]
`
`
`
`
`[58]
`
`
`
`BI-POLAR ELECTROSURGICAL
`
`
`INSTRUMENTS AND METHODS OF
`
`
`
`MAKING
`
`
`
`
`
`
`
`
`Inventors: Philip E. Eggers, Dublin; Andrew R.
`Eggers, Ostrander, both of Ohio
`
`
`
`
`
`
`
`
`
`Assignees Hemostatic Surgery Corporation,
`Georgetown, Cayman Islands
`
`
`
`
`Appl. No.: 265,225
`
`
`
`
`Filed:
`
`
`
`Jun. 24, 1994
`
`
`
`
`
`
`Related U.S. Application Data
`
`
`
`
`
`
`Continuation-in-part of Ser. No. 877,703, May 1, 1992, Pat.
`
`
`
`
`
`
`
`No. 5,324,289, and a continuation-in-part of Ser. No. 877,
`
`
`
`
`
`
`
`704, May 1, 1992, Pat. No. 5,330,471, each is a continua-
`
`
`
`
`
`
`
`
`tion-in-part of Ser. No. 711,920, Jun. 7, 1991, abandoned.
`
`
`
`
`
`
`
`Int. Cl.6 ..................................................... A61B 17/39
`
`
`
`
`
`
`
`
`
`
`U.S. Cl.
`................................. 606/48; 606/47; 606/51;
`606/41
`
`
`
`
`
`
`
`Field of Search .................................. 606/40, 42, 45,
`606/52, 205, 209
`
`
`
`
`[56]
`
`
`
`References Cited
`
`
`U.S. PATENT DOCUMENTS
`
`
`659,409
`9/1900 Mosher.
`
`
`
`1,586,645
`6/1926 Bierman .
`
`
`
`3/1931 Raney .
`1,798,902
`
`
`
`3/1972 Hiltebrandt et al.
`3,651,811
`
`
`
`8/1972 Beurle.
`3,685,518
`
`
`
`5/1973 Ellrnan .
`3,730,188
`
`
`11/1975 Hiltebrandt
`3,920,021
`
`
`
`1/1977 Wien.
`4,003,380
`
`
`
`6/1978 Schneidennan .
`4,092,986
`
`
`
`4,128,099 12/1978 Bauer et al. .
`
`
`
`
`
`
`
`
`11/1980 Herczog .
`4,232,676
`4,271,838
`6/1981 Lasner et al.
`
`
`
`10/1982 Cosman .
`4,353,371
`
`
`
`4,370,980
`2/1983 Lottick .
`
`
`
`1/1985 Auth .......................................... 606/40
`4,492,231
`
`
`
`
`4,590,934
`5/1986 Malis et al.
`.
`
`
`
`
`7/1986 Gati et al.
`............................... 428/161
`4,601,939
`
`
`
`
`
`
`4,643,190
`2/1987 Heimberger .
`
`
`
`4/1987 Tischer .
`4,655,216
`
`
`
`
`
`
`.................... .. 606/51
`
`
`
`
`
`............................... 606/51
`
`
`
`
`......................... .. 606/147
`
`
`
`
`
`
`
`4,669,471
`
`4,671,274
`
`4,763,669
`
`4,784,807
`
`4,819,633
`
`
`6/1987
`6/1987
`8/1988
`11/1988
`4/1989
`
`Hayashi .
`
`
`Sorochenko .
`
`
`Jaeger ..................................... 128/751
`
`
`
`Blanch .
`
`
`Bauer et al.
`
`
`
`
`
`
`(List continued on next page.)
`
`.
`
`
`
`
`
`
`
`FOREIGN PATENT DOCUMENTS
`
`
`1/1978
`France .
`
`
`U.S.S.R. .
`7/1972
`
`
`10/1977
`U.S.S.R. .
`
`
`7/1980
`United Kingdom .
`
`
`
`7/1981
`
`
`
`United Kingdom .
`7/1984
`United Kingdom .
`
`
`
`1/1986
`United Kingdom .
`
`
`
`
`2355521
`
`342617
`575103
`2037167
`2066104
`2133290
`2161082
`
`
`
`
`
`
`
`
`OTHER PUBLICATIONS
`
`
`J. D. K. Burton, The Lancet, “New Inventions” pp. 650—65 1,
`
`
`
`
`
`
`
`
`Oct. 24, 1959.
`
`
`
`S. L. Corson, “Two New Laparoscopic Instruments: Bipolar
`
`
`
`
`
`
`Sterilizing Forceps And Uterine Manipulator”, Medical
`
`
`
`
`
`Instrumentation, Jan.—Feb. 1977.
`
`
`
`
`The Cavitron Bipolar Coagulator, Cavitron Surgical Sys-
`
`
`
`
`
`
`tems, 1979.
`
`
`Primary Examiner—Stephen C. Pellegrino
`
`
`
`
`
`Assistant Examiner-—Michael Pefiley
`Attorney, Agent, or Firm—Fish & Neave; Nicola A. Pisano
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`[57]
`
`
`
`ABSTRACT
`
`
`
`
`
`
`
`
`Bipolar surgical instruments for simultaneously cutting and
`
`
`
`
`
`
`
`coagulating tissue are provided that feature increased manu-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`facturability and durability, reduced component cost and
`
`
`
`
`
`
`reduced assembly requirements. The bipolar instruments
`
`
`
`
`
`
`
`include opposite polarity electrodes isolated by a layer of
`
`
`
`
`
`
`electrical
`insulation deposited and specially prepared to
`reduce electrical breakdown and increase smoothness. A
`
`
`
`
`
`
`
`
`
`
`
`
`pivot pin connecting the electrodes is impregnated with
`
`
`
`
`
`
`
`hydrophobic material, and organic materials are generally
`
`
`
`
`
`
`
`avoided in the components and manufacture of the instru-
`
`
`
`
`
`
`
`ments. A simplified design for an endoscopic bipolar instru-
`
`
`
`
`
`
`
`ment is also provided to reduce cost and improve manufac-
`
`
`
`
`
`
`
`
`turability and durability of such devices.
`
`
`
`
`
`
`
`18 Claims, 5 Drawing Sheets
`
`
`
`
`
`
`
`
`ETHICON ENDO-SURGERY, INC.
`
`EX. 1017
`
`1
`
`

`
`2/1992
`4/1992
`5/1992
`
`9/1992
`9/1992
`6/1994
`7/1994
`2/1995
`
`5,484,436
`Page 2
`
`
`
`
`
`
`
`
`
`
`5,085,659
`5,108,391
`
`5,116,332
`5,147,357
`5,151,102
`
`5,324,289
`
`5,330,471
`
`
`
`5,391,166
`
`
`
`U.S. PATENT DOCUMENTS
`
`
`
`7/1989 Shaw et al. .
`
`
`
`12/1989 Esser et al.
`............................. 128/751
`7/1990 Petillo ......
`.. 604/22
`
`
`
`
`
`
`
`
`
`7/1990
`30/251
`
`
`
`606/38
`11/1990
`
`
`
`. 128/751
`12/1990 Fehling ........
`
`
`
`
`
`.. 606/31
`1/1991 Melzer et al.
`
`
`
`
`4/1991 Reimels .................................... 606/48
`
`
`
`
`
`
`
`4,848,337
`
`4,887,612
`4,940,468
`
`
`4,944,093
`
`4,969,885
`
`4,977,900
`
`4,985,030
`
`5,009,656
`
`
`
`
`
`
`
`
`
`
`Rydell
`..................................... .. 606/47
`
`
`................ .. 606/38
`Flachenecker et al.
`
`
`Lottick ...................................... 606/52
`Rose et al.
`.............................. .. 606/49
`
`
`
`
`
`...................... 606/51
`Kamiyama et al.
`
`
`
`
`
`Eggers ...................................... 606/48
`
`
`
`
`
`Eggers ...................................... 606/48
`
`
`Eggers ...................................... 606/49
`
`
`
`
`
`
`
`
`
`
`
`
`2
`
`

`
`U.S. Patent
`
`
`
`Jan. 16, 1996
`
`
`
`
`Sheet 1 of 5
`
`
`
`5,484,436
`
`
`
`FIG.
`
`
`1
`
`3
`
`

`
`U.S. Patent
`
`
`
`
`Jan. 16, 1996
`
`
`
`
`Sheet 2 of 5
`
`
`5,484,436
`
`
`
`N.6?‘
`
`
`4
`
`

`
`U.S. Patent
`
`
`
`Jan. 16, 1996
`
`
`
`
`Sheet 3 of 5
`
`
`5,484,436
`
`
`
`5
`
`

`
`U.S. Patent
`
`
`
`Jan. 16, 1996
`
`
`
`
`
`
`24
`
`
`
`
`
`Sheet 4 of 5
`
`
`22
`
`
`
`
`
`
`
`
`
`
`
`
`FIG. 4
`
`5,484,436
`
`
`
`
`
`
`
`6
`
`

`
`U.S. Patent
`
`Jan.16, 1996
`
`Sheet 5 of 5
`
`5,484,436
`
`mmat
`
`7
`
`

`
`5,484,436
`
`
`
`1
`
`BI-POLAR ELECTROSURGICAL
`
`
`INSTRUMENTS AND METHODS OF
`
`
`
`MAKING
`
`
`
`
`
`
`This application is a continuation-in—part of commonly
`
`
`
`
`
`
`
`
`assigned and U.S. patent applications Ser. Nos. 07/877,703
`and 07/877,704, both filed May 1, 1992, now U.S. Pat. Nos.
`
`
`
`
`
`
`
`
`
`
`5,324,289, issued Jun. 28, 1994 and 5,330,471, issued Jul.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`19, 1994, respectively, which are continuation-in-part appli-
`cations of U.S. patent application Ser. No. 07/711,920, filed
`
`
`
`
`
`
`
`
`Jun. 7, 1991, abandoned.
`
`
`
`This invention relates to improvements in hemostatic
`
`
`
`
`
`
`
`
`
`bipolar electrosurgical instruments.
`
`10
`
`
`
`BACKGROUND OF THE INVENTION
`
`
`
`
`
`
`
`
`
`instruments which
`Hemostatic bipolar electrosurgical
`both manipulate, or sever, and coagulate tissue are described
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`in copending and commonly assigned U.S. patent applica-
`
`
`
`
`
`
`
`
`
`tions Ser. Nos. 07/877,703 and 07/877,704, both filed May
`1, 1992, now U.S. Pat. Nos. 5,324,289 and 5,330,471,
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`respectively. The text of those patents is incorporated herein
`
`
`
`
`by reference in their entirety.
`The bipolar electrosurgical instruments described in the
`
`
`
`
`
`
`above patents have been well received in the medical
`
`
`
`
`
`
`
`
`
`community. Nevertheless, certain features of the instruments
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`described in those patents have been found to present
`potential obstacles for mass production of these instruments.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`For example, the relatively tight tolerances required for the
`
`
`
`
`
`
`sliding electrical contacts employed in the endoscopic
`
`
`
`
`
`
`
`
`devices described in U.S. patent application Ser. No. 07/877,
`704, now U.S. Pat. No. 5,330,471, have been recognized to
`
`
`
`
`
`
`
`
`
`present potential cost problems when manufactured on a
`
`
`
`
`
`
`
`large scale.
`
`
`
`
`
`
`
`
`It would therefore be desirable to provide improvements
`in both the structure and methods of making bipolar elec-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`trosurgical
`instruments, for use in endoscopic and open
`
`
`
`
`
`
`surgery, which improve the manufacturability and durability
`of the bipolar instruments of the type described in the
`
`
`
`
`
`
`
`
`
`
`
`
`above-incorporated patents.
`
`SUMMARY OF THE INVENTION
`
`
`
`
`In view of the foregoing, it is an object of the present
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`invention to provide improved bipolar electrosurgical instru-
`ments for use in endoscopic and open surgical procedures,
`
`
`
`
`
`
`
`
`and methods of making such instruments, which will
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`improve the manufacturability and durability of such
`devices.
`
`t
`It is, therefore, an object of this invention to provide
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`improvements to the structure of the bipolar electrosurgical
`instruments described in the above-incorporated patents to
`
`
`
`
`
`
`
`improve manufacturability.
`It is another object of this invention to provide methods of
`
`
`
`
`
`
`
`
`
`
`
`
`
`making improved bipolar electrosurgical instruments which
`increase the durability of such instruments.
`
`
`
`
`
`These and other objects are accomplished in accordance
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`with the principles of the present invention by providing
`
`
`
`
`
`
`bipolar electrosurgical instruments having simplified struc-
`tures which are manufactured using improved manufactur-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`ing techniques. The techniques of the present invention
`
`
`
`
`
`
`include: 1) methods of deposition and surface preparation of
`
`
`
`
`
`
`insulative ceramic coatings; 2) impregnation of insulative
`
`
`
`
`
`
`
`pivot pins with electrically insulative hydrophobic material;
`3) elimination of the use of organic insulation materials; 4)
`
`
`
`
`
`
`
`reduction of sharp comers on moving elements to improve
`
`
`
`
`
`
`
`20
`
`
`
`25
`
`
`
`30
`
`
`
`35
`
`
`
`40
`
`
`
`45
`
`50
`
`
`
`55
`
`
`
`60
`
`
`
`65
`
`
`
`2
`
`
`
`
`
`
`
`
`
`insulation uniformity and durability; 5) elimination of slid-
`ing contacts in endoscopic instruments and use of low-cost
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`injection molded parts; _6) use of hardened coatings on
`
`
`
`
`
`
`
`uninsulated shearing faces; and 7) forming of the cutting
`
`
`
`
`
`
`
`
`edges and tissue grasping edges to certain preferred angles.
`
`
`
`
`
`
`
`The foregoing methods and improvements, when imple-
`
`
`
`
`
`
`
`mented in the open—surgery and endoscopic bipolar scissors
`
`
`
`
`
`
`
`described in copending and commonly assigned U.S. patent
`applications Ser. Nos. 07/877,703 and 07/877,704, both filed
`
`
`
`
`
`
`
`
`May 1, 1992, now U.S. Pat. Nos. 5,324,289 and 5,330,471,
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`have been found to enhance manufacturability of such
`
`
`
`
`
`
`
`instruments, to reduce both component and assembly costs,
`and to provide more durable products.
`
`
`
`
`
`
`
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`The above and other objects and advantages of the
`invention will be apparent upon consideration of the fol-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`lowing detailed description, taken in conjunction with the
`accompanying drawings, in which like reference numerals
`
`
`
`
`
`
`refer to like parts throughout, and in which:
`
`
`
`
`
`
`FIG. 1 is an elevated perspective view of an illustrative
`
`
`
`
`
`embodiment of an open—surgery scissor constructed in
`
`
`
`
`
`
`accordance with the present invention;
`
`
`
`
`
`FIG. 2 is an elevated perspective view of an illustrative
`
`
`
`
`
`embodiment of an endoscopic instrument constructed in
`
`
`
`
`
`accordance with the present invention;
`
`
`
`
`
`
`
`
`
`
`
`FIG. 3 is an exploded perspective view of an endoscopic
`
`
`
`
`
`
`
`instrument drive rod and scissor assembly constructed in
`accordance with the present invention;
`
`
`
`
`
`FIG. 4 is a partial cross-sectional view of a scissor blade
`
`
`
`
`
`
`
`
`
`
`
`
`
`showing the included. angle of the insulation layer; and
`FIGS. 5A and SB are sectional views of a charnfered
`
`
`
`
`
`
`
`
`
`graspers constructed in accordance with the present inven-
`
`
`
`
`
`
`
`tion.
`
`
`
`
`
`
`
`
`
`
`
`
`DETAILED DESCRIPTION OF THE
`
`
`INVENTION
`
`The present invention is best understood in the context of
`
`
`
`
`
`
`
`
`
`
`
`
`
`the bipolar electrosurgical instruments described in copend-
`
`
`
`
`
`
`
`
`ing and commonly assigned U.S. patent applications Ser.
`Nos. 07/877,703, now U.S. Pat. No. 5,324,289, and 07/877,
`
`
`
`
`
`
`
`
`
`704, now U.S. Pat. No. 5,330,471, which are incorporated
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`herein by reference. The following detailed description of
`
`
`
`
`
`
`
`
`the present invention is set forth by briefly describing the
`
`
`
`
`
`
`
`instruments set forth in the above-incorporated patents,
`
`
`
`
`
`
`
`followed by a description of the specific improvements
`developed for use in those devices.
`
`
`
`
`
`
`
`
`
`Open Surgery Bipolar Scissors
`
`
`
`
`
`Referring to FIG. 1, bipolar electrosurgical scissors 10 for
`cutting and cauterizing a patient’s tissue are shown as
`
`
`
`
`
`
`
`
`
`
`
`
`illustratively implementing the manufacturing methods of
`the present invention. Scissors 10 of FIG. 1 are constructed
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`as described in copending and commonly assigned U.S.
`patent application 07/877,703, now U.S. Pat. No. 5,324,289,
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`which is incorporated herein in its entirety, except as
`described hereinbelow.
`
`
`Scissors 10 includes first scissor half 11 and second
`
`
`
`
`
`
`
`
`
`scissor half 12 pivotally connected by fastener 13. In one
`
`
`
`
`
`
`
`
`type of scissor described in the above patent, scissor half 11
`
`
`
`
`
`
`
`
`is made of an electrically conducting material and has at one
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`end a first shearing member 14. Shearing member 14 forms
`
`
`
`
`
`
`
`
`
`a first electrode comprising shearing surface 15, cutting edge
`16 and exterior surface 17 (17 is not visible in FIG. 1).
`
`
`
`
`
`
`
`
`
`
`
`Scissor half 11 has, at the other end, support member 18,
`
`
`
`
`
`
`
`
`
`8
`
`

`
`5,484,436
`
`
`
`
`3
`preferably configured with a thumb or finger hole for
`
`
`
`
`
`
`
`manipulating scissors half 11, and electrical connection 19
`
`
`
`
`
`
`
`Which connects the electrode to a power supply 100 via
`
`
`
`
`
`
`
`
`cable 20.
`
`
`Scissor half 12 is likewise made of an electrically con-
`
`
`
`
`
`
`ducting material and has at one end shearing member 21 that
`
`
`
`
`
`
`
`
`
`forms a second electrode, shearing surface 22 (22 is not
`
`
`
`
`
`
`
`
`visible in FIG. 1), cutting edge 23 and exterior surface 24.
`
`
`
`
`
`
`
`
`
`Scissors half 12 likewise includes support member 25 and
`
`
`
`
`
`
`
`electrical connection 26 which connects to power supply
`
`
`
`
`
`
`
`100 via cable 27.
`
`
`
`
`Scissor halves 11 and 12 are preferably made of a rigid,
`
`
`
`
`
`
`
`
`
`
`
`
`
`structural material capable of sustaining sharp scissors-like
`cutting edges 16 and 23, such as stainless steel or martensitic
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`stainless steel. Alternatively, materials of high electrical and
`
`
`
`
`
`
`
`thermal conductivity, and structurally strong enough for
`shearing tissue, such as copper or copper alloys, may be
`
`
`
`
`
`
`
`used. Halves 11 and 12 are pivotally connected by fastener
`
`
`
`
`
`
`
`13 in opposition so that shearing surfaces 15 and 22 and
`
`
`
`
`
`
`
`
`
`cutting edges 16 and 23 of the shearing members move in
`
`
`
`
`
`
`
`scissors-like opposition through a range of motion to sever
`
`
`
`
`
`
`
`
`
`tissue placed therebetween.
`Fastener 13 may be, for example, a screw or a rivet that
`
`
`
`
`
`
`
`electrically insulates scissor halves 11 and 12 at the pivot
`
`
`
`
`
`
`
`
`point. The fastener may be made of an insulative material,
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`for example, ceramic, polyarnide or nylon. Alternatively,
`fastener 13 may comprise a combination of non-insulative
`
`
`
`
`
`
`and insulative materials, such as a stainless steel screw
`
`
`
`
`
`
`
`insulated from one or both scissor halves 11 and 12 by an
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`electrically insulative bushing (e.g., nylon or ceramic).
`Alternatively, fastener 13 may comprise an electrically non-
`
`
`
`
`
`
`insulative material, for example, aluminum, covered with an
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`electrically insulative layer, for example, an anodized alu-
`minum surface.
`
`
`Scissor support members 18 and 25 have insulative coat-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`ing 28 in regions L1 to electrically insulate the support
`members from each other and from the surgeon using
`
`
`
`
`
`
`
`
`
`scissors 10. Insulative coating 28, which may comprise
`
`
`
`
`
`
`
`
`polyvinyl chloride, nylon, or other plastic insulative mate-
`
`
`
`
`
`
`
`rial, also may be applied to those areas of scissors 10 not
`
`
`
`
`
`
`
`
`
`
`used for cutting tissue.
`
`
`
`
`A thin layer 29 of an electrically insulative material is
`
`
`
`
`
`
`disposed on one or both of shearing surfaces 15 and 22 to
`
`
`
`
`
`
`
`cover at least as much of those shearing surfaces as could
`
`
`
`
`
`
`
`contact the other within the full range of motion of scissor
`
`
`
`
`
`
`
`
`
`halves 11 and 12. Insulative layer 29 forms either, or both,
`
`
`
`
`
`
`
`
`
`
`of cutting edges 16 and 23 so that the cutting edges are
`
`
`
`
`
`
`
`
`
`
`electrically inactive and non-conducting. Layer 29 has a
`
`
`
`
`
`
`thickness (or combined thickness, if disposed on both shear-
`
`
`
`
`
`
`
`ing surfaces) in a range of 0.002 inches to about 0.050
`
`
`
`
`
`
`
`
`
`
`inches, and more preferably 0.003 to 0.007 inches.
`
`
`
`
`
`
`
`Insulative layer 29 allows the scissor halves forming the
`
`
`
`
`
`
`
`
`bipolar electrodes to move relative to each other so that
`
`
`
`
`
`
`
`
`
`
`current flows between exterior surface 17 of shearing mem-
`
`
`
`
`
`
`
`ber 14 and exterior surface 24 of shearing member 21, while
`
`
`
`
`
`
`
`ensuring that scissor halves 11 and 12 do not electrically
`
`
`
`
`
`
`
`
`contact each other. This configuration enables the cutting
`
`
`
`
`
`
`
`
`edges to contact each other to sever tissue while preventing
`
`
`
`
`
`
`
`
`short circuiting, which would impede simultaneous coagu-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`lation of the blood vessels extending through the tissue.
`Insulative layer 29 substantially prevents current
`flow
`
`
`
`
`
`
`
`directly between opposing shearing surfaces 15 and 22 when
`
`
`
`
`
`
`
`the scissor halves are closed together. Rather, the current
`
`
`
`
`
`
`
`
`
`flows through the path of least resistance between the
`
`
`
`
`
`
`
`
`
`electrodes, i.e., through the tissue in direct contact with the
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`regions of exterior surfaces 17 and 22 adjacent to the cutting
`
`
`
`
`edges 16 and 23, respectively.
`
`10
`
`
`
`20
`
`
`
`25
`
`
`
`30
`
`35
`
`40
`
`
`
`45
`
`50
`
`
`
`55
`
`
`
`60
`
`
`
`65
`
`
`
`4
`
`
`As described in the above-incorporated U.S. Pat. No.
`
`
`
`
`
`
`
`
`5,324,289, electrically insulative layer 29 may comprise a
`
`
`
`
`
`
`material having a hardness that is greater or substantially
`
`
`
`
`
`
`
`greater than opposing scissor blade member. For example,
`
`
`
`
`
`
`
`
`shearing members 14 and 21 may be made of a martensitic
`
`
`
`
`
`
`stainless steel, e.g., AISI 420, while insulative layer 29
`
`
`
`
`
`
`
`
`
`comprises an inorganic electrically insulative material such
`
`
`
`
`
`
`as a glass, ceramic (e.g., oxide, nitride or boride) or synthetic
`
`
`
`
`
`
`
`
`diamond. Thus, as layer 29 disposed on shearing surface 14
`
`
`
`
`
`
`(as shown in FIG. 1) rubs against the cutting edge 23 or
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`shearing surface 22 of shearing member 21, cutting edge 16
`
`
`
`
`
`
`
`may be sharpened by the harder insulative material 29.
`
`
`
`Endoscopic Bipolar Instruments
`Refening now to FIG. 2, an illustrative bipolar endo-
`
`
`
`
`
`
`
`scopic scissor, such as described in copending and com- '
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`monly assigned U.S. patent application Ser. No. 07/877,704,
`now U.S. Pat. No. 5,330,471, is described as implementing
`
`
`
`
`
`
`
`the improvements of the present invention.
`
`
`
`
`
`
`
`
`
`
`
`Instrument 40 includes actuating means comprising
`handle members 41 and 42 joined for relative movement at
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`pivot 43, tubular elongated barrel 44, and working end 45.
`A drive rod disposed in elongated barrel 44 has electrical
`
`
`
`
`
`
`
`
`
`terminals that are connected to movable members 46 and 47
`
`
`
`
`
`
`
`of working end 45 to provide an electrical potential ther-
`
`
`
`
`
`
`
`
`
`
`
`
`
`ebetween. As described in the above-incorporated patent,
`movable members 46 and 47 may comprise either scissor
`
`
`
`
`
`
`
`blades or grasper members.
`
`
`
`Handle member 41 has a pistol-like configuration, includ-
`
`
`
`
`
`
`ing a body portion 48 having a longitudinal bore 49 and a
`
`
`
`
`
`
`
`portion defining a hole for one or more fingers. Handle
`
`
`
`
`
`
`
`
`member 41 may be made of a light-weight rigid material, for
`
`
`
`
`
`
`
`example cast aluminum or injection molded plastic. Elon-
`
`
`
`
`
`
`
`gated barrel 44 comprises a tube having a proximal end
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`mounted in body portion 48 and a distal portion forming part
`of working end 45. The proximal end of elongated barrel 44
`
`
`
`
`
`
`
`
`
`is mounted in bore 49 of body portion 41 so that elongated
`
`
`
`
`
`
`
`barrel 44 can be rotated about its longitudinal axis. Elon-
`
`
`
`
`
`
`
`
`
`gated barrel may consist of a rigid structural material, for
`
`
`
`
`
`
`
`
`example a stainless steel alloy, e.g., SS 304, and may include
`
`
`
`
`
`
`
`
`
`a coating of electrically insulative material, such as Teflon,
`
`
`
`
`
`
`
`on its exterior surface.
`
`
`
`Knurled rotation knob 50 is mounted on a portion of
`
`
`
`
`
`
`
`
`elongated barrel 44 disposed in body portion 49, so that it
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`projects through slots 51 intersecting bore 49 of body
`portion 41. Rotation of knurled knob 50 causes elongated
`
`
`
`
`
`
`
`
`barrel 44 to rotate about its longitudinal axis, thereby also
`
`
`
`
`
`
`
`
`rotating working end 45. Body member 41 also has a bore
`
`
`
`
`
`
`
`
`
`communicating with bore 49 so that a set screw disposed in
`
`
`
`
`
`
`
`the bore engages elongated barrel 44 substantially perpen-
`
`
`
`
`
`
`
`dicularly to the longitudinal axis of the barrel. The set screw
`
`
`
`
`
`
`
`
`includes locking knob 52 to lock elongated barrel 44 at a
`
`
`
`
`
`
`
`desired orientation.
`
`
`Handle member 42 has a lower portion defining a finger
`
`
`
`
`
`
`
`or thumb hole and an upper portion 53 having longitudinal
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`bore 54. Longitudinal bore 54 aligns with longitudinal bore
`49 in body portion 48 of handle member 41 when handle
`
`
`
`
`
`
`
`members 41 and 42 are joined for relative movement at pivot
`
`
`
`
`
`
`
`43. Handle member 42 comprises a similar material as
`
`
`
`
`
`
`
`handle member 41, e.g., a cast aluminum alloy.
`
`
`
`
`
`
`Drive rod 55 has proximal end 56 disposed within elon-
`
`
`
`
`
`
`
`
`gated barrel 44 and a distal end engaged with working end
`
`
`
`
`
`
`
`
`
`45. Proximal end 56 of the drive rod has electrical terminals
`
`
`
`
`
`
`
`
`
`57 projecting from its proximal endface. Drive rod 55 either
`
`
`
`
`
`
`
`
`comprises or is covered by an electrically insulative material
`
`
`
`
`
`to electrically isolate it from handle members 41 and 42 and
`
`
`
`
`
`
`
`
`elongated barrel 44 when electrical terminals 57 are con-
`
`
`
`
`
`
`
`
`
`
`9
`
`

`
`6
`
`5,484,436
`
`
`
`5
`
`
`nected to a power supply. Drive rod 55 includes a groove
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`that is captured in disk 58 between pins 59. Disk 58 seats in
`a circular aperture in upper portion 53 of handle member 42
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`and is capable of angular movement in the circular aperture,
`when handle member 42 rotates relative to handle member
`
`
`
`
`
`
`
`
`
`
`
`41 about pivot 43.
`
`
`
`
`
`
`Scissors-like working end 45 includes diametrically
`
`
`
`
`
`
`
`
`opposed U-shaped slots 60 extending proximally from the
`
`
`
`
`
`
`
`
`distal endface of elongated barrel 44. Apertures 61 in the
`distal end of elongated barrel 44 are aligned across the
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`diameter of the barrel to accept insulative pivot pin 62. As
`shown in FIG. 2, insulative pivot pin 62 has its ends flush
`
`
`
`
`
`
`
`
`
`with the outer surface of elongated barrel 44 and extends,
`
`
`
`
`
`
`
`
`
`
`from side to side, through movable members 46 and 47, and
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`may comprise an electrically insulative metallic pin, e.g.,
`anodized aluminum.
`
`
`For the illustrative embodiment shown in FIG. 2, movable
`
`
`
`
`
`
`
`members 46 and 47 comprise scissor halves pivotally con-
`
`
`
`
`
`
`
`nected by insulative pivot pin 62. Movable members 46 and
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`47 include, respectively, shearing surfaces 63 and 64 (64 is
`not visible in FIG. 2), cutting edges 65 and 66, and exterior
`
`
`
`
`
`
`
`
`
`
`surfaces 67 and 68 (68 is not visible in FIG. 2). In one
`
`
`
`
`
`
`
`
`
`
`
`preferred embodiment of instrument 40, movable members
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`46 and 47 may be constructed of metallic alloys that oifer
`
`
`
`
`
`
`
`good electrical conduction, adequate hardness and tensile
`strength suflicient to allow the members to be oriented
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`toward each other to effect adequate wiping at the cutting
`
`
`
`
`
`
`
`edges. Suitable materials include, for example, stainless
`steels, martensitic stainless steels and precipitation hardened
`
`
`
`
`
`
`
`steels.
`
`A thin layer 69 of insulative coating is provided on one or
`
`
`
`
`
`
`both of the opposing mating surfaces of movable members
`
`
`
`
`
`
`
`46 and 47, including one or both of the shearing surfaces 63
`
`
`
`
`
`
`
`
`
`and 64 to form one or both of cutting edges 65 and 66, which
`
`
`
`
`
`
`
`
`are electrically isolated from each other. Thus, as in instru-
`
`
`
`
`
`
`
`
`ment 10 described hereinabove, current flows between exte-
`
`
`
`
`
`
`
`rior surfaces 67 and 68 of movable members 46 and 47 in a
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`region near cutting edges 65 and 66, while ensuring that
`movable members 46 and 47 do not electrically contact each
`
`
`
`
`
`
`
`other within the range of the cutting motion of the members.
`
`
`
`
`
`
`
`
`
`Layer 69 has a thickness (or combined thickness, if disposed
`
`
`
`
`
`
`
`on both mating surfaces) in a range of 0.002 inches to about
`
`
`
`
`
`
`
`
`0.050 inches, and more preferably 0.003 to 0.007 inches.
`
`
`
`
`
`
`
`
`Improvements Of The present Invention
`
`
`
`
`In View of the foregoing illustrative devices, the present
`
`
`
`
`
`
`
`
`invention provides a number of improvements to those
`
`
`
`
`
`
`
`
`
`
`
`devices which increase manufacturability, durability and
`product safety. The techniques of the present
`invention
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`include: 1) methods of deposition and surface preparation of
`
`
`
`
`
`
`insulative ceramic coatings; 2) impregnation of insulative
`
`
`
`
`
`
`
`pivot pins with electrically insulative hydrophobic material;
`3) elimination of the use of organic insulation materials; 4)
`
`
`
`
`
`
`
`reduction of sharp comers on moving elements to improve
`
`
`
`
`
`
`
`
`
`
`
`
`
`insulation uniformity and durability; 5) endoscopic instru-
`ment component simplification; 6) use of hardened coatings
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`on uninsulated shearing faces; and 7) forming of the cutting
`
`
`
`
`
`
`
`
`edges and tissue grasping edges to certain preferred angles.
`The foregoing improvements are described seriatirn here-
`
`
`
`
`
`
`
`inbelow.
`
`1. Ceramic Insulative Layers
`
`
`
`
`With respect to the bipolar scissors illustrated in FIGS. 1
`
`
`
`
`
`
`
`and 2, insulative layer 29 of instrument 10 and insulative
`
`
`
`
`
`
`
`
`
`
`
`
`
`layer 69 of instrument 40 may be disposed on one shearing
`face or both shearing faces by any number of methods, for
`
`
`
`
`
`
`
`
`example, plasma deposition or the use of a ceramic inset
`
`
`
`
`
`
`
`bonded to the shearing face.
`
`
`
`
`
`10
`
`
`
`20
`
`
`
`25
`
`
`
`30
`
`
`
`35
`
`
`
`40
`
`
`
`45
`
`
`
`50
`
`55
`
`
`
`60
`
`
`
`65
`
`
`
`10
`
`
`
`
`
`
`
`
`In conventional plasma deposition techniques, deposited
`
`
`
`
`
`
`material is applied at subsonic velocities. Applicants have
`
`
`
`
`
`
`
`determined, however, that by applying the insulative mate-
`
`
`
`
`
`
`
`rial, for example, aluminum oxide, at supersonic velocities,
`the density of the ceramic layer can be increased and the
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`porosity of the resulting layer decreased relative to conven-
`
`
`
`
`
`
`
`tional methods. Applicants have developed these supersonic
`deposition techniques, for use in the instruments of the
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`present invention, in cooperation with Thermal Spray Tech-
`nologies, Watertown, Wis. This process is available from
`
`
`
`
`
`
`
`Thermal Spray Technologies under the tradename HVOF
`
`
`
`
`
`
`
`
`
`
`
`(High Velocity OxyFuel process).
`
`
`
`
`
`
`
`
`The increased density of the ceramic layer resulting from
`
`
`
`
`
`
`deposition at supersonic velocities improves the smoothness
`
`
`
`
`
`
`
`
`
`
`of insulative layers 29 and 69, while the resulting higher
`
`
`
`
`
`
`
`
`
`density also improves the wear resistance of the layers. The
`
`
`
`
`
`
`
`reduced porosity which accompanies higher density pre-
`vents ingress of biological fluids (e.g., blood, saline) into the
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`pores of the insulative layer, thereby improving the ability to
`clean and sterilize instruments 10 and 40, and thus reduce
`
`
`
`
`
`
`
`
`
`
`pyrogen levels between uses.
`
`
`
`
`
`
`
`
`
`
`
`Depending upon the composition of the substrate upon
`
`
`
`
`
`
`
`
`which the ceramic is to be deposited, it may further be
`
`
`
`
`
`
`
`desirable to suitably prepare the substrate, for example,
`
`
`
`
`
`
`
`using a conventional bonding layer or grit blasting,
`to
`improve adhesion of the ceramic to the substrate.
`
`
`
`
`
`
`
`
`
`
`
`
`
`In addition to increasing density of the insulative coating
`
`
`
`
`
`
`through improved plasma deposition techniques, applicants
`
`
`
`
`
`
`
`
`
`have found that the smoothness of the insulative layer can be
`
`
`
`
`
`further improved by post—deposition polishing. In particular,
`
`
`
`
`
`
`
`
`
`polishing the insulative layers 29 and 69 with a fine grit
`
`
`
`
`
`
`
`polishing wheel, for example,
`the Scotch-Brite bufiing
`
`
`
`
`
`
`wheels available from Minnesota Mining & Manufacturing
`
`
`
`
`
`
`Company, Minneapolis, Minn., improves the smoothness of
`the scissors cutting action, reduces wear on the uninsulated
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`scissors half, and further reduces ingress of biological fluids
`into the pores of the insulative layer.
`
`
`
`
`
`
`Applicants have also determined that wear of the ceramic
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`insulative layer can be reduced by disposing the insulative
`layer on only one shearing face, rather than on both shearing
`
`
`
`
`
`
`
`
`
`surfaces. In addition to reducing wear on the insulative layer
`
`
`
`
`
`
`29 or 69, this technique permits the uninsulated half to be
`
`
`
`
`
`
`
`
`shaped to maximize cutting performance. Thus,
`for
`
`
`
`
`
`
`
`example,
`the uninsulated scissor halve may be bent as
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`desired so that its cutting edge rubs with adequate force
`against the insulative layer disposed on the other scissor
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`half. By contrast, such a tuning operation may damage the
`insulative layer where both shearing faces include an insu-
`
`
`
`
`
`
`
`
`
`
`lative layer.
`2. Impregnation Of Pivot Pins
`
`
`
`
`The illustrative embodiments of FIGS. 1 and 2 each
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`include an insulative pivot pin, 13 and 62, respectively, that
`electrically insulate scissor halves 11 and 12 and movable
`
`
`
`
`
`
`
`
`members 46 and 47 from one another. Because the pivot pin
`
`
`
`
`
`
`
`
`
`experiences the full voltage differential across it when the
`
`
`
`
`
`
`
`instruments 10 and 40 are energized, the pivot pin must be
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`rugged enough to withstand both high electrical duty and
`mechanical wear.
`
`
`
`
`
`
`
`
`